This invention relates to an image forming apparatus which requires high voltage output adjustment, and also to a connected-object detecting method for detecting before the high voltage output adjustment whether or not an adjustment tool is connected to the apparatus instead of a development unit.
Electrophotography image forming apparatuses are equipped with high voltage transformers. In these apparatuses, a high voltage obtained from the high voltage transformer is applied to a charger, a developing device, etc. incorporated therein. To adjust the high voltage output of the transformer, it is considered necessary to dismount a developing unit including the developing device. If the high voltage output of the transformer is adjusted with the developing unit mounted, it is possible that (1) a charger voltage will be output and a developing bias will not be output, thereby causing a developer to fall, or that (2) the developing bias will be output and the charger voltage will not be output, thereby causing toner to scatter.
In each of those cases, the apparatus may well be much adversely affected. To avoid this, the high voltage output adjustment must be performed with the developing unit dismounted and a dedicated adjustment tool mounted instead. At the present stage, the mounting of the dedicated adjustment tool is confirmed mainly visually.
Such visual confirmation, however, is not considered a thorough enough measure. Further, if a detection unit for detecting the mounting of the tool is employed, the cost of the apparatus will inevitably increase.